Hi, I am on a mac and recently updated to R 3.6.2 and trying to download Bioconductor using:

source("http://bioconductor.org/biocLite.R")

but get the error:

Error: With R version 3.5 or greater, install Bioconductor packages using BiocManager; see https://bioconductor.org/install

So I go to the link and enter the provided code:

    if (!requireNamespace("BiocManager", quietly = TRUE))
    install.packages("BiocManager")
BiocManager::install(version = "3.10")

but get the following error:

Bioconductor version 3.10 (BiocManager 1.30.10), R 3.6.2 (2019-12-12)
Old packages: 'digest', 'ps'
Update all/some/none? [a/s/n]: 
a

  There are binary versions available but the source versions are later:
       binary source needs_compilation
digest 0.6.23 0.6.24              TRUE
ps      1.3.0  1.3.2              TRUE

Do you want to install from sources the packages which need compilation? (Yes/no/cancel) Yes
installing the source packages ‘digest’, ‘ps’

trying URL 'https://cran.rstudio.com/src/contrib/digest_0.6.24.tar.gz'
Content type 'application/x-gzip' length 145526 bytes (142 KB)

==================================================
downloaded 142 KB

trying URL 'https://cran.rstudio.com/src/contrib/ps_1.3.2.tar.gz'
Content type 'application/x-gzip' length 98761 bytes (96 KB)

==================================================
downloaded 96 KB

* installing *source* package ‘digest’ ...
** package ‘digest’ successfully unpacked and MD5 sums checked
** using staged installation
** libs
xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
**ERROR: compilation failed for package ‘digest’**
* removing ‘/Library/Frameworks/R.framework/Versions/3.6/Resources/library/digest’
* restoring previous ‘/Library/Frameworks/R.framework/Versions/3.6/Resources/library/digest’
* installing *source* package ‘ps’ ...
** package ‘ps’ successfully unpacked and MD5 sums checked
** using staged installation
** libs
xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
**ERROR: compilation failed for package ‘ps’**
* removing ‘/Library/Frameworks/R.framework/Versions/3.6/Resources/library/ps’
* restoring previous ‘/Library/Frameworks/R.framework/Versions/3.6/Resources/library/ps’

The downloaded source packages are in
    ‘/private/var/folders/nx/_07512cx3cdfz3464ts6glqw0000gn/T/RtmpWI9bpo/downloaded_packages’
Warning messages:
1: In install.packages(update[instlib == l, "Package"], l, repos = repos,  :
  **installation of package ‘digest’ had non-zero exit status**
2: In install.packages(update[instlib == l, "Package"], l, repos = repos,  :
  **installation of package ‘ps’ had non-zero exit status**

Any help or suggestions is appreciated. Thank you for your time.

Please note that surrounding your code with triple back-ticks, or simply highlighting and clicking the box with 101010 will make your code much more readable.

Anyway, the critical part of the error is this:

xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun

And if you were to google that (like I just did) you will get something that may be helpful? This seems to be due to some dark arts having to do with XCode.